CPU-Z is not available for Mac but there are a few alternatives that runs on macOS with similar functionality. The best Mac alternative is CheckMyMac. It's not free, so if you're looking for a free alternative, you could try System Information or MacCPUID. If that doesn't suit you, our users have ranked more than 25 alternatives to CPU-Z and four of them are available for Mac so hopefully you can find a suitable replacement.
System Information provides detailed specifications and other information about your Mac hardware and software, including your network and external devices. In some versions of OS X, this app is called System Profiler.
SystemPal is becoming an ALL-IN-ONE app. It is the best tool to monitor your memory/CPU usage status, CPU temperature and fan speed, network speed. It also provides a tool kit including mini music player, screen shot utility, memory cleaner.